PROJECT SUMMARY/ABSTRACT The aim of this research project is to address minority health disparities in vascular brain aging and to begin to identify modifiable factors that may contribute to these disparities. Up to half of all cases of Alzheimer?s disease are attributable to modifiable risk factors including vascular risks factors like hypertension and diabetes. Research has shown that African Americans are disproportionately affected by vascular risk factors and their negative impact on cognition and brain aging when compared to Caucasian Americans; less is known about how this increased susceptibility to vascular brain aging may be impacted by potentially modifiable environmental or ?neighborhood? factors. Shown to contribute to cardiovascular disease and stroke, neighborhood factors including crime rates, availability of healthy and less healthy food may ?set the stage? or even ?set in motion? a cascade of individual conditions including vascular risk factors that may negatively impact brain outcomes. Thus, new insights may be gained by exploring the impact of neighborhood factors before cardiovascular disease and stroke. In fact, a comprehensive evaluation of individuals with high and low- to-no vascular risk would provide understanding of both the negative and positive impact neighborhood factors may have on brain aging. When combined with innovations in magnetic resonance imaging (MRI) that hold promise in identifying ?at risk? brain tissue before overt damage occurs, this study may provide targets for future interventions to reduce minority health disparities associated with vascular brain aging. This study is a logical extension of the PI?s K01, an NIA-funded methods grant focused on comparing traditional and more novel techniques including MRI myelin mapping to characterize ?at risk? white matter in individuals with elevated vascular risk. K01 data suggests ?at risk? brain tissue is evident within white matter of such individuals as is executive dysfunction and to a greater extent in African Americans. While the K01 includes a small sample of African Americans with elevated vascular risk, it does not include African Americans or Caucasian Americans with low-to-no vascular risk. Furthermore, the K01 is not equipped to answer the question of how neighborhood factors might contribute to this profile of risk (or resiliency for that matter). In this R21, we propose to recruit and perform novel MRI myelin mapping techniques and cognitive assessments in 25 African American and 25 Caucasian Americans with low-to-no vascular risk to compare to African Americans and Caucasian Americans with elevated vascular risk who are studied as part of the K01. Only with the R21 will we be able to investigate the complex interplay of environmental and biological factors that may impact susceptibility to vascular disease and brain aging in African Americans. By combining a novel and sensitive MRI technique with neighborhood factors, we will be the first to contribute to the larger dialogue regarding future directions for treatment and services involving potentially modifiable neighborhood factors that may reduce minority health disparities in vascular brain aging.